feat(frontend): Implement Phase 1 - ProjectManagement API Client & Hooks

Add complete API integration for ProjectManagement module:
- Epics, Stories, Tasks API clients
- React Query hooks for all entities
- Updated type definitions to match backend API
- API test page for connection verification

Changes:
- Update lib/api/config.ts: Add all ProjectManagement endpoints
- Update types/project.ts: Match backend API models (Epic, Story, Task)
- Create lib/api/pm.ts: API clients for Epics, Stories, Tasks
- Create lib/hooks/use-epics.ts: React Query hooks for Epic CRUD
- Create lib/hooks/use-stories.ts: React Query hooks for Story CRUD
- Create lib/hooks/use-tasks.ts: React Query hooks for Task CRUD
- Create app/(dashboard)/api-test/page.tsx: API connection test page

Features:
- Full CRUD operations for Epics, Stories, Tasks
- Status change and assignment operations
- Optimistic updates for better UX
- Error handling with toast notifications
- Query invalidation for cache consistency

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

types/project.ts

@@ -1,90 +1,129 @@
-export type ProjectStatus = 'Active' | 'Archived' | 'OnHold';
+// ==================== Common Types ====================
+export type WorkItemStatus = 'Backlog' | 'Todo' | 'InProgress' | 'Done';
+export type WorkItemPriority = 'Low' | 'Medium' | 'High' | 'Critical';
 
+// ==================== Project ====================
 export interface Project {
   id: string;
   name: string;
-  description: string;
   key: string;
-  status: ProjectStatus;
-  ownerId: string;
+  description?: string;
+  tenantId: string;
   createdAt: string;
-  updatedAt?: string;
+  updatedAt: string;
 }
 
 export interface CreateProjectDto {
   name: string;
-  description: string;
   key: string;
-  ownerId?: string; // Optional in form, will be set automatically
+  description?: string;
 }
 
 export interface UpdateProjectDto {
-  name?: string;
+  name: string;
+  key: string;
   description?: string;
-  status?: ProjectStatus;
 }
 
+// ==================== Epic ====================
 export interface Epic {
   id: string;
-  name: string;
-  description: string;
+  title: string;
+  description?: string;
   projectId: string;
-  status: TaskStatus;
-  priority: TaskPriority;
+  status: WorkItemStatus;
+  priority: WorkItemPriority;
+  estimatedHours?: number;
+  actualHours?: number;
+  assigneeId?: string;
+  tenantId: string;
   createdAt: string;
-  createdBy: string;
+  updatedAt: string;
 }
 
-export type TaskStatus = 'ToDo' | 'InProgress' | 'InReview' | 'Done' | 'Blocked';
-export type TaskPriority = 'Low' | 'Medium' | 'High' | 'Urgent';
+export interface CreateEpicDto {
+  projectId: string;
+  title: string;
+  description?: string;
+  priority: WorkItemPriority;
+  estimatedHours?: number;
+}
 
+export interface UpdateEpicDto {
+  title?: string;
+  description?: string;
+  priority?: WorkItemPriority;
+  estimatedHours?: number;
+  actualHours?: number;
+}
+
+// ==================== Story ====================
 export interface Story {
   id: string;
   title: string;
-  description: string;
+  description?: string;
   epicId: string;
-  status: TaskStatus;
-  priority: TaskPriority;
+  projectId: string;
+  status: WorkItemStatus;
+  priority: WorkItemPriority;
   estimatedHours?: number;
   actualHours?: number;
   assigneeId?: string;
-  createdBy: string;
+  tenantId: string;
   createdAt: string;
-  updatedAt?: string;
+  updatedAt: string;
 }
 
+export interface CreateStoryDto {
+  epicId: string;
+  title: string;
+  description?: string;
+  priority: WorkItemPriority;
+  estimatedHours?: number;
+}
+
+export interface UpdateStoryDto {
+  title?: string;
+  description?: string;
+  priority?: WorkItemPriority;
+  estimatedHours?: number;
+  actualHours?: number;
+}
+
+// ==================== Task ====================
 export interface Task {
   id: string;
   title: string;
-  description: string;
+  description?: string;
   storyId: string;
-  status: TaskStatus;
-  priority: TaskPriority;
+  projectId: string;
+  status: WorkItemStatus;
+  priority: WorkItemPriority;
   estimatedHours?: number;
   actualHours?: number;
   assigneeId?: string;
-  customFields?: Record<string, any>;
-  createdBy: string;
+  tenantId: string;
   createdAt: string;
-  updatedAt?: string;
+  updatedAt: string;
 }
 
 export interface CreateTaskDto {
-  title: string;
-  description: string;
   storyId: string;
-  priority: TaskPriority;
+  title: string;
+  description?: string;
+  priority: WorkItemPriority;
   estimatedHours?: number;
-  assigneeId?: string;
 }
 
 export interface UpdateTaskDto {
   title?: string;
   description?: string;
-  status?: TaskStatus;
-  priority?: TaskPriority;
+  priority?: WorkItemPriority;
   estimatedHours?: number;
   actualHours?: number;
-  assigneeId?: string;
-  customFields?: Record<string, any>;
 }
+
+// ==================== Legacy Types (for backward compatibility) ====================
+// Keep old type names as aliases for gradual migration
+export type TaskStatus = WorkItemStatus;
+export type TaskPriority = WorkItemPriority;